It is still a lot easier to remember information like “Portuguese people tend to eat dinner late” than “the average Portuguese dinner time is from <some UTC offset> to <some other UTC offset>”.
This is really an incredibly narrow use-case in the modern world. It's very easy to ignore a phone call nowadays if you're busy. Avoiding global times just to gain an incredibly inaccurate estimate of when someone might be busy is not a very compelling argument.
